Vehicle suspension system

ABSTRACT

A vehicle axle suspension which may be employed in a single or multiple axle arrangement and which is characterized by a rigid elongate mounting arm disposed at each side of the vehicle frame with its forward end pivoted to a bracket depending from the frame and its trailing end connected to the wheel axle beneath an air cushion which is interposed between the axle and the frame and a snubber-like force absorbing device connecting an intermediate portion of the mounting arm with the frame at a point spaced rearwardly of the pivoted end of the mounting arm.

United States Patent Hendrickson 45] Apr. 4, 1972 VEHICLE SUSPENSIONSYSTEM Robert T. Hendrickson, Lyons, lll.

Assignee: Hendrickson Mfg. Co., Lyons, Ill.

Filed: May 18, 1970 Appl. No.: 38,385

Inventor:

U.S. Cl. ...280/124 F, 267/15 R Int. Cl ..B60g 11/26 Field of Search..267/15 R, 15 A; 280/124 References Cited UNITED STATES PATENTS l/l968Harbers ..280/124 8/1962 Geyer ..280/l24 Primary Examiner-Philip GoodmanAttorneyGreist, Lockwood, Greenawalt & Dewey [5 7] ABSTRACT A vehicleaxle suspension which may be employed in a single or multiple axlearrangement and which is characterized by a rigid elongate mounting armdisposed at each side of the vehicle frame with its forward end pivotedto a bracket depending from the frame and its trailing end connected tothe wheel axle beneath an air cushion which is interposed between theaxle and the frame and a snubber-like force absorbing device connectingan intermediate portion of the mounting arm with the frame at a pointspaced rearwardly of the pivoted end of the mounting arm.

9 Claims, 6 Drawing Figures PATENTEDAPR 4 I972 SHEET 2 OF 3 NIH im B/ WeFM" M 1 6T6? gTa i INVENTOR ROBERT T HENDRUGON PATENTEUAPR 4:912

sums 0F 3 ROZERT T HENDRICKSON INVENTOR ATT' Y5.

VEHICLE SUSPENSION SYSTEM This invention relates generally to wheelsupported vehicles and is more particularly concerned with innovationsand improvements in apparatus for providing a resilient suspensionsystem connecting the vehicle frame and a wheel axle or axles.

Various suspension systems have been provided heretofore for connectinga vehicle frame to wheel axle assemblies so as to provide a satisfactorysupport fro the vehicle under various operating conditions. Systems havebeen devised for supporting the vehicle and its load under static ormoving conditions wherein the axle assemblies are connected to rigid armmembers which in turn have had some form of resilient connection withthe vehicle frame. One form of resilient suspension system of this typeis disclosed in my U.S. Pat. No. 2,689,136, dated Sept. 14, 1954 andU.S. Pat. No. 3,297,339 dated Jan. 10, 1967, in which tandem axles areconnected to opposite ends of rigid walking beams which have a pivotalconnection intermediate their ends with brackets resiliently mounted independing relation on the vehicle side frame members. Another form ofresilient suspension is disclosed in my U.S. Pat. No. 3,130,952, datedFeb. 1 l, 1964 which employs cantilever beam members for supporting asingle axle assembly. While these suspensions are satisfactory for thepurposes for which the respective systems have been designed, there hasnot been available a rigid arm suspension system which may be employedin a single axle arrangement and by duplication of the single axlearrangement provide a satisfactory multiple axle arrangement.

It is a general object of the invention to provide a resilientsuspension system for supporting a vehicle frame on one or more wheelaxles wherein a novel suspension unit is employed for each axle whichunit is so constructed that it may be satisfactorily employed for asingle axle suspension or by duplication for tandem or other multipleaxle suspension arrangements.

It is a more specific object of the invention to provide a vehiclesuspension employing a rigid cantilever arm which is connected at itsforward end to the vehicle frame and at the rearward end to an axle withlimited movement of the arm permitted by an air cushion interposedbetween the wheel axle and the vehicle frame and a force absorbingdevice which functions as a snubber connecting the arm at a pointintermediate its ends with the vehicle frame.

A still more specific object of the invention is to provide a vehiclesuspension wherein an axle is mounted on the ends of elongate cantileverarms having their leading ends pivotally connected to brackets dependingfromthe vehicle side frame members with air cushions interposed betweenthe axles and the frame member and with force absorbing devicesconnecting the frame members and intermediate portions of the cantileverarms which devices are operative as snubbers when the air cushions areextended and which also absorb side sway forces and support rebound.

Another object of the invention is to provide a vehicle suspension whichemploys cantilever arms disposed at opposite sides of the vehicle framewhich arms are pivotally mounted at their forward ends on bracketsdepending from the side frame members and extend rearwardly along thesame with their rearward ends pivotally connected to brackets dependingfrom an axle assembly below air spring members connecting the axleassembly to the frame, the arms being connected intermediate their endsto the overlying frame by a force absorbing device whereby the arms tendto pull the frame down when the wheels go over a bump thereby minimizingbouncing.

These and other objects and advantages of the invention will be apparentfrom a consideration of the vehicle suspension system which is shown byway of illustration in the accompanying drawings wherein:

FIG. 1 is an elevational view, with portions broken away, at one side ofa vehicle frame showing a suspension system for a single wheel axleassembly which embodies the principal features of the invention;

FIG. 2 is a partial rear elevation showing the suspension system of FIG.1;

FIG. 3 is a partial plan view showing the suspension system of FIG. 1;

FIG. 4 is an enlarged view with portions broken away of the forceabsorbing device which connects the pivoted arm at a point intermediateits ends to the vehicle frame;

FIG. 5 is a cross section taken on the line 5-5 of FIG. 1, to anenlarged scale; and

FIG. 6 is a side elevation illustrating a multiple axle suspensionsystem embodying the invention.

Referring to FIGS. 1 to 4, there is illustrated a rear portion of awheel supported vehicle frame 10 which comprises laterally spaced,parallel side frame members in the form of channels 11, an end crosschannel 12 connecting the ends of the side frame members 11 and anintermediate double channel, reinforcing cross frame member 13. A singleaxle suspension arrangement extends beneath the vehicle frame 10 with aconnection to each side frame member 11. The connecting structure 15 isduplicated at each side of the frame 11 and only one such connectingstructure or suspension arrangement 15 will be described.

The suspension assembly or arrangement 15 at each side of the frame 11comprises a bracket 16, which may be a metal casting, and which 'isrigidly attached by bolts or other fasteners to the outside and bottomfaces of the vehicle side frame channel 11. The bracket 16 has adepending portion 17 extending in the direction forwardly of the vehicleframe 11, with a pivot bearing 18 for accommodating a pivot pin assembly20 which connects thereto the leading or forward end of an elongaterigid cantilever arm 21. The cantilever arm 21 extends rearwardly of thepivot 20 and has a pivot bearing 22 at the rear end for receiving apivot pin assembly 23 in the inverted U-shaped bracket 24 which connectsthereto the axle assembly 25, the latter having its end extended toreceive a pair of wheels 26.

The axle assembly 25 which extends transversely of the frame 10 isconnected to the side frame member 11 above the pivot 23 by means of anair cushion or air spring assembly 27 and a bracket 28, with the latterbeing spaced rearwardly of the bracket 16. Various forms or styles ofair cushion assemblies may be employed. In the form of air cushion 27which is illustrated, top and bottom plates 30 and 31 are separated by apair of air bags 32 of rubber-like material which constitute air ride orair spring members, each having a girdle hoop 33 dividing it into twosections and encompassing a bumper member 34 of rubber or otherresilient material extending upwardly of the bottom plate 31 whichlimits the compression of the spring forming member 32. The top plate 30is connected to the bracket 28 which is of inverted T-shaped crosssection and which is bolted or otherwise secured to the outside andbottom faces of the side frame member 11. The bottom plate 31 isconnected in a suitable manner to the top of the axle housing 25. A tankvalve (not shown) is provided for entrance of air into the member 32.

The forward bracket 16 extends rearwardly and has a depending rearportion 36 forming a cylindrical housing for a depending pin 37, theupper end of which extends into the housing, with the lower endextending below the bracket portion 36. A resilient stress-absorbingassembly 38 is carried on the extended lower end of the pin 37, which isseated in a cylindrical recess 40 provided in the beam member 21intermediate the ends thereof. The stress-absorbing unit or assembly 38,in the form illustrated, is composed of two concentrically arrangedsleeve members 41 and 42, of metal or other rigid material, between theconfronting faces of which there is provided a cylindrical bushing 43,of rubber or other resilient material, the inner and outer faces ofwhich are bonded to the confronting faces of the rigid sleeve members 41and 42. The inner sleeve member 41 is mounted on the end of the pin 37and the assembly 38 is retained thereon by a washer forming member 44secured by a nut 45 on a threaded stud formation 46 which is rigidlysecured in the lower end of the tubular member which constitutes the pin37. The outer sleeve 42 is seated in the recess 40 and the assembly 38is held in the recess by clamp members 47 mounted on studs 48 which arespaced about the periphery of the recess 40 and engage a clamping washer50. The washer 50 forms an inwardly directed flange on the top edge ofthe outer sleeve 42 with the inner margins overlying the resilientbushing 43. The width and shape of the washer margin may be varied tovary the contact with the upper face of the resilient bushing 43 andthus limit the upward movement of the latter. In like manner, the bottomwasher 44 may have its marginal portions varied to limit the movement ofthe bushing 43 in the downward direction. Thus, variations in the rideor snubbing action of the assembly 38 may be had.

The pivot assemblies 20 and 23 at opposite ends of the cantilever arm 21may take the form illustrated in FIG. 5, or any similar form which willpermit some limited movement or twisting action between the machines. Inthe form illustrated in FIG. 5, the parallel plate-like legs 52 and 52'of the bracket 24 have aligned apertures or bores 53 and 53 in which thepivot assembly 23 is mounted. The pivot assembly or bushing 23 comprisesa cylindrical inner metal sleeve 54 which is clamped in position betweenthe bores 53 and 53' in the legs 52 and 52 and receives the inner endsof flanged plug members 55 and 55' which are connected by a bolt 56. Anouter cylindrical metal sleeve 57 is seated in the bearing recess 22 inthe end of the arm member 21 and a cushion forming cylindrical sleeve 58of rubber or other rubber-like material is interposed between the innerand outer sleeve members 54 and 57 and bonded thereto. The arm member 21and the outer sleeve 57 are of lesser dimensions in the direction of theaxis of the inner sleeve member 54 than the corresponding dimension ofthe latter and the outer end faces of the rubber sleeve 58 are taperedinwardly at 59 and 59 which permits a limited amount of twistingmovement between the arm 21 and bracket 24.

The air cushion or air spring assembly 27 permits limited verticalmovement in response to vertical forces due to weight and load and thepin carried assembly 38 acts as a snubber. It also acts to absorbstresses due to side-sway. The arrangement eliminates any need forradius or torque rods or other bracing against side-sway. The usualtorque rod 60 for countering any tendency of the axle assembly 25 torotate about its transverse axis may be connected at one end to the axlehousing at 61 and at the other end to the cross frame member 13 at 62 asshown in FIGS. 1 and 2.

A tandem suspension is shown in FIG. 6 which illustrates the employmentof the invention in producing a multiple axle suspension system. In theillustrated arrangement, two single axle suspension 15 and 15 areemployed for supporting the vehicle frame on the parallel axles 25 and25. The rearmost axle 25 carrying wheels 26 is connected to the frameside channels 11 by the suspension while the forward axle 25' carryingwheels 26 is connected to a portion of the frame 10 at points spacedforwardly of the suspension 15. The axle 15 is attached to the ends ofthe cantilever arms 21 by a pivot bearings 23, the other ends of thearms 21 being connected by pivot bearings to depending portions 17 ofthe mounting brackets 16 which are fixed on the side frame channels 11.An air cushion or air spring 27 is interposed between the axle and amounting bracket 28 on each side frame member 11 while a force absorbingdevice 38 on the bottom of a pin 37 depending from each bracket 16 isconnected to the midpoint of each of the cantilever arms. The suspension15 duplicates the suspension 15 and like parts are indicated by the samenumbers primed. The mounting brackets 16 and 28 are secured to the sideframe members 11 at points spaced forwardly of the correspondingmounting brackets 16 and 28 as shown and center torque bars (not shown)may be employed to resist rotation ofthe axles 25 and 25'.

lclaim:

l. A resilient axle suspension interposed between each'side of a vehicleframe and the transversely extending axle of a wheel support meanstherefor comprising an elongate rigid arm member disposed beneath theframe side member and extending longitudinally of the vehicle, amounting bracket for said arm member having a depending portion at theforward end thereof and pivot means connecting the forward end of saidrigid arm member to said depending forward endportion of said mountingbracket so as to permit vertical swinging movement of said rigid armmember, pivot forming means at the other end of said arm member, abracket depending from said transversely extending axle and connected tosaid arm member by said pivot forming means at the other end of said armmember, an air cushion mounted between said transversely extending axleand said vehicle frame and a stress absorbing device connecting said armmember at a point intermediate its ends with the vehicle frame at thetrailing end of the mounting bracket for said arm member which stressabsorbing device acts as a snubber when the air cushion is extended.

2. An axle suspension as set forth in claim 1 and said stress absorbingdevice comprising a pin depending from said frame side member with thebottom end thereof connected to said arm member by a resilient sleevebushing which permits limited swinging movement of said arm member in avertical direction.

3. An axle suspension as set forth in claim 1 and said stress absorbingdevice comprising a rigid pin depending from a rearward portion of saidmounting bracket and a resilient bushing on said pin which is seated ina recess in said arm member and which permits limited swinging movementof said arm member.

4. An axle suspension as set forth in claim 1 and said pivot means atthe end of said arm member including a resilient bushing.

5. A resilient axle suspension structure for a vehicle having a framewith parallel side beams and a wheel support means having a transverselyextending axle, said suspension structure comprising an elongate rigidarm member disposed beneath each frame side beam and extendinglongitudinally of the vehicle, a mounting bracket for each said armmember at the forward end thereof and pivot means connecting the forwardend of said arm member to said mounting bracket so as to permit verticalswinging movement of said arm member, pivot means at the other end ofsaid arm member connecting said arm member to said transverselyextending axle, a cushion forming means comprising a resilientcompressible air member mounted between said transversely extending axleand said vehicle frame, and means including a stress absorbing deviceconnecting said arm member at a point intermediate its ends with theframe side beam which acts as a snubber when the cushion forming meansis extended.

6. A resilient axle suspension structure as set forth in claim 5 whereinsaid cushion forming means comprises an air spring member.

7. A resilient suspension unit for single or multiple axle support of avehicle frame, said suspension unit comprising an elongate rigid armmember disposed beneath the vehicle frame at each side thereof andextending longitudinally of the vehicle, a mounting bracket for said armmember depending below said vehicle frame, pivot means connecting theforward end of said arm member to said depending mounting bracket so asto permit vertical swinging movement of said arm member, pivot means atthe other end of said arm member connecting said arm member to atransversely extending axle, said pivot means at the opposite ends ofsaid arm member having a resilient member so as to permit limitedtwisting movement, means forming a cushion member mounted between saidtransversely extending axle and said vehicle frame and a stressabsorbing device connecting said arm member at a point intermediate itsends with the overlying vehicle frame which device acts as a snubber forthe cushion member.

8. A resilient suspension unit for single or multiple axle support of avehicle frame, said suspension unit comprising an elongate rigid armmember disposed beneath the vehicle frame at each side thereof andextending longitudinally of the vehicle, a mounting bracket for said armmember depending below said vehicle frame, pivot means connecting theforward end of said arm member to said depending mounting bracket so asto permit vertical swinging movement of said arm member, pivot means atthe other end of said arm member connecting said arm member to atransversely extending axle, means forming a cushion member mountedbetween said transversely extending axle and said vehicle frame and astress absorbing device connecting said arm member at a pointintermediate its ends with the overlying vehicle frame, said stressabsorbing device comprising a rigid pin depending from said frame and aresilient connection between the lowermost end of said pin and said armmember which resilient connection includes a resilient sleeve secured onthe end of said pin, said arm member having a socket for receiving saidresilient sleeve, and means for securing said resilient sleeve in saidsocket which permits limited vertical movement of said pin end andenables side sway to be absorbed by said resilient sleeve while actingas a snubber for limiting the movement of said arm member when saidcushion member is extended.

9. A resilient axle suspension structure for a vehicle having 'a framewith parallel side beams and a wheel support means having a transverselyextending axle. said suspension structure comprising an elongate rigidarm member disposed beneath each frame side beam and extendinglongitudinally of the vehicle, a mounting bracket for each said armmember at the forward end thereof and pivot means connecting the forwardend of said arm member to said forward mounting bracket so as to permitvertical swinging movement of said arm mem ber. pivot means at the otherend of said arm member connecting said arm member to said transverselyextending axle, a cushion forming means mounted between saidtransversely extending axle and said vehicle frame and a stressabsorbing device in the form of a rigid pin depending from said vehicleframe which pin extends into a cooperating socket formation in said armmember at a point intermediate its ends with a resilient sleeve bushingconnection so as to act as a snubber when the cushion forming means isextended.

1. A resilient axle suspension interposed between each side of a vehicleframe and the transversely extending axle of a wheel support meanstherefor comprising an elongate rigid arm member disposed beneath theframe side member and extending longitudinally of the vehicle, amounting bracket for said arm member having a depending portion at theforward end thereof and pivot means connecting the forward end of saidrigid arm member to said depending forward end portion of said mountingbracket so as to permit vertical swinging movement of said rigid armmember, pivot forming means at the other end of said arm member, abracket depending from said transversely extending axle and connected tosaid arm member by said pivot forming means at the other end of said armmember, an air cushion mounted between said transversely extending axleand said vehicle frame and a stress absorbing device connecting said armmember at a point intermediate its ends with the vehicle frame at thetrailing end of the mounting bracket for said arm member which stressabsorbing device acts as a snubber when the air cushion is extended. 2.An axle suspension as set forth in claim 1 and said stress absorbingdevice comprising a pin depending from said frame side member with thebottom end thereof connected to said arm member by a resilient sleevebushing which permits limited swinging movement of said arm member in avertical direction.
 3. An axle suspension as set forth in claim 1 andsaid stress absorbing device comprising a rigid pin depending from arearward portion of said mounting bracket and a resilient bushing onsaid pin which is seated in a recess in said arm member and whichpermits limited swinging movement of said arm member.
 4. An axlesuspension as set forth in claim 1 and said pivot means at the end ofsaid arm member including a resilient bushing.
 5. A resilient axlesuspension structure for a vehicle having a frame with parallel sidebeams and a wheel support means having a transversely extending axle,said suspension structure comprising an elongate rigid arm memberdisposed beneath each frame side beam and extending longitudinally ofthe vehicle, a mounting bracket for each said arm member at the forwardend thereof and pivot means connecting the forward end of said armmember to said mounting bracket so as to permit vertical swingingmovement of said arm member, pivot means at the other end of said armmember connecting said arm member to said transversely extending axle, acushion forming means comprising a resilient compressible air membermounted between said transversely extending axle and said vehicle fRame,and means including a stress absorbing device connecting said arm memberat a point intermediate its ends with the frame side beam which acts asa snubber when the cushion forming means is extended.
 6. A resilientaxle suspension structure as set forth in claim 5 wherein said cushionforming means comprises an air spring member.
 7. A resilient suspensionunit for single or multiple axle support of a vehicle frame, saidsuspension unit comprising an elongate rigid arm member disposed beneaththe vehicle frame at each side thereof and extending longitudinally ofthe vehicle, a mounting bracket for said arm member depending below saidvehicle frame, pivot means connecting the forward end of said arm memberto said depending mounting bracket so as to permit vertical swingingmovement of said arm member, pivot means at the other end of said armmember connecting said arm member to a transversely extending axle, saidpivot means at the opposite ends of said arm member having a resilientmember so as to permit limited twisting movement, means forming acushion member mounted between said transversely extending axle and saidvehicle frame and a stress absorbing device connecting said arm memberat a point intermediate its ends with the overlying vehicle frame whichdevice acts as a snubber for the cushion member.
 8. A resilientsuspension unit for single or multiple axle support of a vehicle frame,said suspension unit comprising an elongate rigid arm member disposedbeneath the vehicle frame at each side thereof and extendinglongitudinally of the vehicle, a mounting bracket for said arm memberdepending below said vehicle frame, pivot means connecting the forwardend of said arm member to said depending mounting bracket so as topermit vertical swinging movement of said arm member, pivot means at theother end of said arm member connecting said arm member to atransversely extending axle, means forming a cushion member mountedbetween said transversely extending axle and said vehicle frame and astress absorbing device connecting said arm member at a pointintermediate its ends with the overlying vehicle frame, said stressabsorbing device comprising a rigid pin depending from said frame and aresilient connection between the lowermost end of said pin and said armmember which resilient connection includes a resilient sleeve secured onthe end of said pin, said arm member having a socket for receiving saidresilient sleeve, and means for securing said resilient sleeve in saidsocket which permits limited vertical movement of said pin end andenables side sway to be absorbed by said resilient sleeve while actingas a snubber for limiting the movement of said arm member when saidcushion member is extended.
 9. A resilient axle suspension structure fora vehicle having a frame with parallel side beams and a wheel supportmeans having a transversely extending axle, said suspension structurecomprising an elongate rigid arm member disposed beneath each frame sidebeam and extending longitudinally of the vehicle, a mounting bracket foreach said arm member at the forward end thereof and pivot meansconnecting the forward end of said arm member to said forward mountingbracket so as to permit vertical swinging movement of said arm member,pivot means at the other end of said arm member connecting said armmember to said transversely extending axle, a cushion forming meansmounted between said transversely extending axle and said vehicle frameand a stress absorbing device in the form of a rigid pin depending fromsaid vehicle frame which pin extends into a cooperating socket formationin said arm member at a point intermediate its ends with a resilientsleeve bushing connection so as to act as a snubber when the cushionforming means is extended.